As the deployment of wireless ad-hoc networks increases, the available capacity per wireless node decreases. This is because the number of nodes contending for the wireless channel increases. For example, consider a single wireless channel with CSMA as the access protocol. As the number of nodes increases, the channel occupancy increases and the chance for a particular node to sense an idle channel therefore decreases. In such cases, using more than one wireless channel can increase the capacity, since the number of contending nodes per channel would decrease.
Normally, an ad-hoc network would have several frequencies to choose from, where the main challenge is to have the nodes choose frequencies with low occupancy. Since, however, the wireless nodes operate in an ad-hoc manner, there is little co-ordination possible for such a task. Accordingly, there is a need for nodes to dynamically select frequencies with low occupancy in a manner that results in minimizing the search for such frequencies and the risk of a large of number of nodes choosing the same frequency.